This invention relates to cordless electric grass cutting devices such as battery-powered lawnmowers, shears and the like. More particularly, this invention relates to such electric grass cutting devices having removable batteries.
To substantially eliminate the exhaust emissions from gasoline-powered lawnmowers and the like, and for the sake of convenience, battery-powered grass cutting devices have been developed. More recently, battery-powered grass cutting devices have been developed which have removable and interchangeable batteries.
One advantage of using interchangeable batteries is that when the battery or batteries discharge, they may simply be replaced by one or more fully charged batteries. As a result, the cutting time is extended. Another advantage of this approach is that the operational weight of the grass cutting device may be reduced since smaller batteries may be used in place of the large, bulkier batteries which are typically necessary to achieve significant cutting time if the batteries are not interchangeable.
Yet another advantage of using removable batteries is that if the battery is not built into the fixed mower housing, the battery may be recharged without moving the entire mower to a source of line current. This is an important advantage when the mower is stored in a shed that does not have electrical power.
To increase the output of a battery-powered grass cutting device, it is desirable to provide one or more batteries having a total output of 24 volts instead of a single 12 volt battery. The use of one or more batteries presents a problem with proper weight distribution. If a single 24 volt battery, or two 12 volt batteries, are placed in front of the electric motor, the weight of the device is not properly balanced. Also, if the batteries are placed behind the motor, they tend to interfere with the raised scroll used for rear bagging operations. If one 12 volt battery is placed on top of another 12 volt battery, then the height of the cutting device may be significantly increased, and the device is not aesthetically pleasing.